Harry Smith's motocross future was in doubt after thieves broke into his family's backyard last week and stole his two motorcycles - a KTM 85 and CR 125.

The 15-year-old was heartbroken, faced with the knowledge his family could not afford to replace the bikes which are worth about $9000.

But Harry's mum Sally said response from the community has been unbelievable.

"Someone lent Harry a bike to ride at the weekend to keep his points going," she said.

"The support has just been insane.

"People we don't even know have been offering their help.

"It's all been on Facebook and shared everywhere and it's just grown and grown and grown."

Sally said police were still investigating the theft.

She said she was overwhelmed by the kindness of strangers.

"A man from Ballarat saw us racing at Maryborough and he said, 'Look, you don't know me at all but I've been watching this kid race and he's a kid who has to be racing'," Sally said.

"This bloke said, 'He has to be on a bike. He can't be lost to the sport'.

"So they're organising this massive fundraiser over at Maryborough.

"I don't know the details but it's in the pipeline.

"It's unbelievable what everyone is doing."

Harry has been riding motorbikes since he was two.

"I've gone through a number of bikes and I've broken both my legs, one arm and my sternum," he said.

"I went A Grade when I was nine or 10."

When the Bendigo Advertiser visited the Smith's home the day after the theft, Sally described the situation as "devastating".

"They obviously knew what they were doing," she said.

"They've obviously seen us coming in and out and know where the bikes are.

"It's just sickening to think they've been watching us.

"We are absolutely distraught.

"We were all up last night, none of us have slept.

"We were frightened they were going to come back last night."